Steve was posting pics of this at 3:00AM? Talk about burning the midnight oil!

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Glad you brought that up.  I made the first unit with adjustable input impedance and dropped it down low enough to work with moving coil and was less than impressed.  It did not sound better than using the moving coil transformer.  I used the Fidelity Research FR7f and matching step up transformer for the test.

What does sound good is running the output of the step up transformer into this cartridge amplifier.  In fact it takes it to another level exactly like it does the Moving Magnet cartridges.  So, this is where the name "Zen Cartridge Amplifier" will be coming from.  It is not specifically designed for moving magnet but moving magnet OR moving coil/step up transformer combination.  Basically it is set up for a 47K input.

I put the order in yesterday for the ZCA chassis at our Illinois metal working supplier assuming anything that creeps up in continued testing can be easily solved without a brand new chassis.

Also, on another note, I don't remember if I mentioned this or not, but this unit can be used as a tool for evaluating tonearms.  You simply turn your system volume all the way up and the ZCA volume all the way up.  At this level you can just about hear a nat fly past the tonearm, so tapping on it, scratching it with your fingernail, touching the arm board, all can be very enlightening especially when comparing one arm to another.  Whatever you hear, dull textured sound vs. tiny reverberant sound is going to be super imposed on the music at a very subtle level.  One that you could never isolate and hear during playback but a sound that will be excited by the midrange frequencies in the music that match the sound you hear during the scratch and tap testing.

So all is going well so far.  Battery life on this second unit as predicted is going to be poor.  I'm still working out how poor.  I have changed the batteries once so far by setting an arbitrary cut off point of 5 volts.  I should see how low I can get it, but I don't have time to wade into distortion and lower output because it will skew my judgement of it and right now there are things about it I like better than the first version.

I may experiment with a 6 volt DC jack on the rear as an option so that a person could use that in place of the D-Cell batteries.  I am waiting to see how long the 9 volt battery lasts before I do anything.  No charging circuit in this one, don't want the complexity and don't want to limit battery types.  If I add a jack it will be for an external regulated linear power supply that a customer could supply.  They are popular on ebay and aliexpress for a couple hundred bucks.

Thats OK Steve. It was probably unintentional misleading li(n)es anyhow

I am looking at several new tables some with MC cartridges included. Your sediment about the use of a MC with the ZCA is noted.

I think an optional power plug is a good idea adding flexibility.